[jbsp]

Hi all,
Having a lot of trouble with gmsh trying to do an axisymmetric pipe flow. The issue I am having is where the boundary layer on the outside meets the inlet line. The boundary layer elements get highly skewed. How do I tell gmsh to continue the boundary to the inlet to avoid this?

An image is here: https://imgur.com/a/mq8TkHD



gmsh file:

grid_size = 0.05;

Point(1) = {0,0,0,grid_size};
Point(2) = {1,0,0,grid_size};
Point(3) = {1,1,0,grid_size};
Point(4) = {0,1,0,grid_size};

Line(5) = {1,2}; //inlet
Line(6) = {2,3}; //tunnel wall
Line(7) = {3,4}; //outlet
Line(8) = {4,1}; //axis of rotation

Line Loop(9) = {5,6,7,8};
Plane Surface(10) = 9;

// Boundary layers:
Field[1] = BoundaryLayer;
Field[1].EdgesList = {6};
Field[1].hfar = 0.05;
Field[1].hwall_n = 0.00005;
Field[1].Quads = 1;
BoundaryLayer Field = 1;